XTender and XTender2 are ZX81 emulators for MS/DOS (Windows compatible).

XTender is a
classic "1st generation" emulator, existing since 1991 and running the vast
majority of ZX81 programs at unsurpassed speed on XT/AT/386/486
systems. XTender is a shareware product and
has many thousands of devoted users.

XTender2 is a
"2nd generation" emulator, written by the same author. XTender2 is superior to XTender
in all respects. It requires a 1GHz Pentium
system (or better) to run smoothly. XTender2 is currently a freeware product
at beta-testing stage. Download your evaluation copy below.

Features of XTender2
include:

Emulates many different
systems, for example ZX80, ZX81, Aszmic, PC-8300, or even a user-developed
system.

Can run ZX81 programs
directly from the DOS commandline, or by double-clicking a P-file
in Windows (so you don't have to type a LOAD "..." command inside the emulator).

Can auto-stop ZX81
programs immediately after loading.

Can load & save
ZX80 programs from & to disk in O-files.

Supports both SLOW
and FAST mode, and also intermediate modes (as generated by specific
tools).

Very realistic video
output - not seen before on any other ZX81 emulator - because
XTender2 includes a TV-emulator:
your PC monitor responds like a real TV-set when the ZX81 does not provide
proper video timing (this happens in FAST-mode, for example). XTender2 lets your screen flicker, flash, tremble
and roll, very similar to what you would see on the real thing!

Provides an excellent
keyboard interface. The keyboard will never lock, multiple
simultaneous keypresses are possible, and even keyboard matrix errors
are emulated correctly!

Supports PC-keyboards
with QWERTY, AZERTY and QWERTZ layout

Produces graphical
printer output.

Includes a virtual
tape interface: save/load your data to/from a virtual tape recorder
and watch the tape signals being echoed to the screen! The virtual tape
interface is the ultimate method to get data into and from any system
(including ZX80, ZX81 and Aszmic) and/or by any original (fast) Save/Load
tool that you ever may have used. Original tape recordings can
be converted to virtual tape files, and vice versa.

Has a very flexible
interface to the "outside world" via non-intrusive user-definable ROM-patches
that are fully invisible for the emulated system (PEEK, etc.) and that are
handled by external programs (i.e. not by XTender2
itself).